... The school is fine, actually very good, but I don't think my son's needs are being met. I think he's getting bored. He has said many times this year that he's learned nothing in class, and that he only learns outside of school... I'm frustrated that my son needs to be learning at a higher level than his school is willing/able to provide, but there are no solid options for him.
I'm sorry to say, "Welcome to the club". In fact, your experiences actually sound more fortunate than those shared by many families. For decades parents have been evaluating schools, providing feedback, and cobbling together an education for their childrens' needs, often in an unwelcoming atmosphere.
Many gifted kiddos are homeschooled for at least a portion of their academic careers. There are many curriculum resources shared on the gifted forums.
There are also many advocacy tips, approaches, and resources on gifted forums. Because you mention your school has at least experimented with your sons' placement in a class with higher grade level curriculum, you may wish to invest time in researching these approaches and make a checklist to follow, requesting a meeting with a team at the school when your sons needs are clear, you have specific goals in mind, and you have evidence to advocate for them.
Many families have found that requesting "more" from a school did not lead to creative solutions, but showing a body of evidence regarding needs and goals can be more effective in partnering for change.
